Less than a month after a series of unprecedented wildfires devastated several Northern California communities, controversy has ignited over who is at fault.

In an event that the state’s Department of Forestry and Fire Protection (CalFire) referred to as the “October Siege," more than 11,000 firefighters battled more than 250 fires across the state. The worst fires cut a path of devastation through Lake, Mendocino, Napa and Sonoma Counties, just north of San Francisco. The fires there forced over 100,000 residents to evacuate, destroyed more than 8,000 structures and took 42 lives.

Pacific Gas & Electric (PG&E) is the provider of power for the region that was devastated by the fires. The utility initiated a rapid response to restore gas and electric service to hundreds of thousands of its customers.

In an equally rapid response, numerous customers have filed suit against the utility, claiming its power lines were the cause of the fires. CalFire is responsible for determining the cause of the fires and has released no statements indicating what the cause may have been. It is currently studying the issue, and it may take months or years to formally determine the cause of the fires.

Customers aren't going to wait. The San Francisco Chronicle reported that over 120 plaintiffs have already filed more than 15 lawsuits. The lawsuits claim that PG&E is responsible for property losses because fires were caused by sparks from its power lines.

The utility is fighting back. In a filing related to the lawsuits, PG&E asserts that the deadliest fire, the "Tubbs Fire," may have been caused by electrical equipment that was not owned by the utility.

The statement refers to an electric incident report that the utility submitted to state regulators. That report states that on Wednesday, Oct. 26, 2017, near the City of Calistoga, Napa County, CalFire took possession of a set of three in-service distribution line fused cutouts, two sets of in-service transformer fused cutouts, and a secondary service line that had detached from a fire-damaged home. CalFire also took possession of multiple sections of a customer-owned overhead conductor that served multiple pieces of customer-owned equipment on the property.

Should PG&E be held liable, it would be another devastating blow for the utility's finances and reputation. Two years ago, the California Public Utility Commission (PUC) levied a $1.6 billion penalty on the utility for causing a gas explosion in the town of San Bruno in 2010 that killed eight people. In January of this year, a Judge slapped the utility with an additional $3 million fine and convicted the company of six felonies for the disaster. In April of this year, the PUC also fined PG&E $8 million for causing a fire in Amador County in 2015. That fire destroyed more than 900 structures and killed two people.